The invention relates to a process for producing a converted synthesis gas from a crude synthesis gas comprising the essential synthesis gas constituents of hydrogen (H.sub.2) and carbon monoxide (CO), wherein the crude synthesis gas is initially generated in a synthesis gas generation stage and subsequently converted in a multi-stage CO conversion and thus elevated in terms of its hydrogen content. The crude synthesis gas has steam added to it as a reaction partner for the CO conversion and cooling of the converted synthesis gas affords an aqueous condensate.

A water decomposition device may include a hydrogen-generating electrode including a first external electrode and at least one first internal electrode formed integrally with the first external electrode, and an oxygen-generating electrode including a second external electrode and at least one second internal electrode formed integrally with the second external electrode. The first external electrode and the second external electrode are disposed to face each other, and the first internal electrode and the second internal electrode are disposed alternately in a direction perpendicular to the longitudinal direction thereof. Therefore, the water decomposition device may secure both transparency and durability even when an opaque material is used therefor.

In the thermochemical water splitting process by the CuCl cycle, oxygen gas is produced by a thermolysis process in a three-phase reactor. A precise knowledge of the hydrodynamic and heat transfer analyses is required for the scale-up of the thermolysis reactor. However, in the experimental studies of the scale up analysis, there are some challenges in using the actual materials of the thermolysis reactor products (i.e. molten salt CuCl and oxygen gas). In accordance with the teachings herein, alternative materials are defined, by using dimensional analyses, to simulate the hydrodynamic and heat transfer behaviors of the actual materials. It has been found that these alternative materials are liquid water at 222 C. and helium gas at 902 C. The alternative materials provide safe environment for the experimental runs as well as lower operating temperature. Furthermore, these alternative materials are more readily available and are low cost.

A system and method for producing hydrogen, including converting sulfur vapor and oxygen gas in a first zone of furnace into sulfur monoxide, injecting water into a second zone of the furnace, converting the sulfur monoxide and the water in the second zone into hydrogen gas and sulfur dioxide, discharging furnace exhaust gas (including the hydrogen gas) from the furnace, condensing sulfur vapor in the furnace exhaust gas into liquid sulfur in a condenser (heat exchanger) downstream of the furnace, and discharging the liquid sulfur from the condenser to a vessel.

A method for producing hydrogen of the present invention includes thermally reducing a reaction medium in which CeO.sub.2 is doped with a metal other than Ce and bringing the thermally reduced reaction medium into contact with water to oxidize the reaction medium and to generate the hydrogen. When a reaction temperature in the thermally reducing the reaction medium is defined as T1 [ C.] and a reaction temperature in the bringing the thermally reduced reaction medium into contact with the water is defined as T2 [ C.], a relation of T1T2150 is satisfied. It is preferred that a series of processes including the thermally reducing the reaction medium and the bringing the thermally reduced reaction medium into contact with the water is repeated.

A method of and apparatus for optimizing a hydrogen producing system is provided. The method of optimizing the hydrogen producing system comprises producing hydrogen gas using a hydrogen producing formulation and removing a chemical substance that reduces the hydrogen gas producing efficiency. Further, the hydrogen producing system comprises a hydrogen producing catalyst, a hydrogen generating voltage applied to the hydrogen producing catalyst to generate hydrogen gas, and a catalyst regenerating device to regenerate the hydrogen producing catalyst to a chemical state capable of generating the hydrogen gas when a hydrogen generating voltage is applied.

A hydrogen production system includes: hydrogen compound members, a first container, a second container having an internal temperature that is lower than the internal temperature of the first container, and a water supplying device that supplies water to the second container. The hydrogen compound member accommodated in the first container is movable into the second container, and the hydrogen compound member accommodated in the second container is movable into the first container.

The system of the invention is capable to safely generate a continuous controlled hydrogen flow. The passive auto sufficient hydrogen system of the invention is very valuable for example for emergency power back up, propulsion application, battery charging or powering portable devices.

Also the present invention refers to a chemical process for generating hydrogen using alkali metals, alkaline earth metals, hydrides of alkali metals or hydrides of earth alkali metals to obtain primary by products from water. Then the primary by products reacts with a metal reactant to obtain additional hydrogen.

A method of and apparatus for optimizing a hydrogen producing system is provided. The method of optimizing the hydrogen producing system comprises producing hydrogen gas using a hydrogen producing formulation and removing a chemical substance that reduces the hydrogen gas producing efficiency. Further, the hydrogen producing system comprises a hydrogen producing catalyst, a hydrogen generating voltage applied to the hydrogen producing catalyst to generate hydrogen gas, and a catalyst regenerating device to regenerate the hydrogen producing catalyst to a chemical state capable of generating the hydrogen gas when a hydrogen generating voltage is applied.

The present disclosure relates to a processes and systems for producing fuels from biomass with high carbon conversion efficiency. The processes and systems described herein provide a highly efficient process for producing hydrocarbons from biomass with very low Green House Gas (GHG) emissions using a specific combination of components, process flows, and recycle streams. The processes and systems described herein provide a carbon conversion efficiency greater than 95% with little to no GHG in the flue gas due to the novel arrangement of components and utilizes renewable energy to provide energy to some components. The system reuses water and carbon dioxide produced in the process flows and recycles naphtha and tail gas streams to other units in the system for additional conversion to syngas to produce hydrocarbon-based fuels.